Environmental drivers of increased ecosystem respiration in a warming tundra

Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.

Trap-integrated fluorescence detection with silicon photomultipliers for sympathetic laser cooling in a cryogenic Penning trap

We present a fluorescence-detection system for laser-cooled 9Be+ ions based on silicon photomultipliers (SiPMs) operated at 4 K and integrated into our cryogenic 1.9 T multi-Penning-trap system. Our approach enables fluorescence detection in a hermetically sealed cryogenic Penning-trap chamber with limited optical access, where state-of-the-art detection using a telescope and photomultipliers at room temperature would be extremely difficult. We characterize the properties of the SiPM in a cryocooler at 4 K, where we measure a dark count rate below 1 s-1 and a detection efficiency of 2.5(3)%. We further discuss the design of our cryogenic fluorescence-detection trap and analyze the performance of our detection system by fluorescence spectroscopy of 9Be+ ion clouds during several runs of our sympathetic laser-cooling experiment.

BASE-STEP: A transportable antiproton reservoir for fundamental interaction studies

Currently, the world's only source of low-energy antiprotons is the AD/ELENA facility located at CERN. To date, all precision measurements on single antiprotons have been conducted at this facility and provide stringent tests of fundamental interactions and their symmetries. However, magnetic field fluctuations from the facility operation limit the precision of upcoming measurements. To overcome this limitation, we have designed the transportable antiproton trap system BASE-STEP to relocate antiprotons to laboratories with a calm magnetic environment. We anticipate that the transportable antiproton trap will facilitate enhanced tests of charge, parity, and time-reversal invariance with antiprotons and provide new experimental possibilities of using transported antiprotons and other accelerator-produced exotic ions. We present here the technical design of the transportable trap system. This includes the transportable superconducting magnet, the cryogenic inlay consisting of the trap stack and detection systems, and the differential pumping section to suppress the residual gas flow into the cryogenic trap chamber.

Ultra-thin polymer foil cryogenic window for antiproton deceleration and storage

We present the design and characterization of a cryogenic window based on an ultra-thin aluminized biaxially oriented polyethylene terephthalate foil at T < 10 K, which can withstand a pressure difference larger than 1 bar at a leak rate <1×10-9 mbar l/s. Its thickness of ∼1.7 μm makes it transparent to various types of particles over a broad energy range. To optimize the transfer of 100 keV antiprotons through the window, we tested the degrading properties of different aluminum coated polymer foils of thicknesses between 900 and 2160 nm, concluding that 1760 nm foil decelerates antiprotons to an average energy of 5 keV. We have also explicitly studied the permeation as a function of coating thickness and temperature and have performed extensive thermal and mechanical endurance and stress tests. Our final design integrated into the experiment has an effective open surface consisting of seven holes with a diameter of 1 mm and will transmit up to 2.5% of the injected 100 keV antiproton beam delivered by the Antiproton Decelerator and Extra Low ENergy Antiproton ring facility of CERN.

BASE-high-precision comparisons of the fundamental properties of protons and antiprotons

Abstract

The BASE collaboration at the antiproton decelerator/ELENA facility of CERN compares the fundamental properties of protons and antiprotons with ultra-high precision. Using advanced Penning trap systems, we have measured the proton and antiproton magnetic moments with fractional uncertainties of 300 parts in a trillion (p.p.t.) and 1.5 parts in a billion (p.p.b.), respectively. The combined measurements improve the resolution of the previous best test in that sector by more than a factor of 3000. Very recently, we have compared the antiproton/proton charge-to-mass ratios with a fractional precision of 16 p.p.t., which improved the previous best measurement by a factor of 4.3. These results allowed us also to perform a differential matter/antimatter clock comparison test to limits better than 3 %. Our measurements enable us to set limits on 22 coefficients of CPT- and Lorentz-violating standard model extensions (SME) and to search for potentially asymmetric interactions between antimatter and dark matter. In this article, we review some of the recent achievements and outline recent progress towards a planned improved measurement of the antiproton magnetic moment with an at least tenfold improved fractional accuracy.

Graphic Abstract

Urachal carcinoma: a large retrospective multicentric study from the French Genito-Urinary Tumor Group

Introduction

Urachal cancer (UrC) is a rare, non-urothelial malignancy. Its natural history and management are poorly understood. Although localized to the bladder dome, the most common histological subtype of UrC is adenocarcinoma. UrC develops from an embryonic remnant, and is frequently diagnosed in advanced stage with poor prognosis. The treatment is not standardized, and based only on case reports and small series. This large retrospective multicentric study was conducted by the French Genito-Urinary Tumor Group to gain a better understanding of UrC.

Material and Methods

data has been collected retrospectively on 97 patients treated at 22 French Cancer Centers between 1996 and 2020.

Results

The median follow-up was 59 months (range 44-96). The median age at diagnosis was 53 years (range 20-86), 45% were females and 23% had tobacco exposure. For patients with localized disease (Mayo I-II, n=46) and with lymph-node invasion (Mayo III, n=13) median progression-free-survival (mPFS) was 31 months (95% CI: 20-67) and 7 months (95% CI: 6-not reached (NR)), and median overall survival (mOS) was 73 months (95% CI: 57-NR) and 22 months (95% CI: 21-NR) respectively. For 45 patients with Mayo I-III had secondary metastatic progression, and 20 patients were metastatic at diagnosis. Metastatic localization was peritoneal for 54% of patients. Most patients with localized tumor were treated with partial cystectomy, with mPFS of 20 months (95% CI: 14-49), and only 12 patients received adjuvant therapy. Metastatic patients (Mayo IV) had a mOS of 23 months (95% CI: 19-33) and 69% received a platin-fluorouracil combination treatment.

Conclusion

UrC is a rare tumor of the bladder where patients are younger with a higher number of females, and a lower tobacco exposure than in standard urothelial carcinoma. For localized tumor, partial cystectomy is recommended. The mOS and mPFS were low, notably for patients with lymph node invasion. For metastatic patients the prognosis is poor and standard therapy is not well-defined. Further clinical and biological knowledge are needed.

A high-Q superconducting toroidal medium frequency detection system with a capacitively adjustable frequency range >180 kHz

We describe a newly developed polytetrafluoroethylene/copper capacitor driven by a cryogenic piezoelectric slip-stick stage and demonstrate with the chosen layout cryogenic capacitance tuning of ≈60 pF at ≈10 pF background capacitance. Connected to a highly sensitive superconducting toroidal LC circuit, we demonstrate tuning of the resonant frequency between 345 and 685 kHz, at quality factors Q > 100 000. Connected to a cryogenic ultra low noise amplifier, a frequency tuning range between 520 and 710 kHz is reached, while quality factors Q > 86 000 are achieved. This new device can be used as a versatile image current detector in high-precision Penning-trap experiments or as an LC-circuit-based haloscope detector to search for the conversion of axion-like dark matter to radio-frequency photons. This new development increases the sensitive detection bandwidth of our axion haloscope by a factor of ≈1000.

Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.

A 16-parts-per-trillion measurement of the antiproton-to-proton charge-mass ratio

The standard model of particle physics is both incredibly successful and glaringly incomplete. Among the questions left open is the striking imbalance of matter and antimatter in the observable universe¹, which inspires experiments to compare the fundamental properties of matter/antimatter conjugates with high precision^2-5. Our experiments deal with direct investigations of the fundamental properties of protons and antiprotons, performing spectroscopy in advanced cryogenic Penning trap systems⁶. For instance, we previously compared the proton/antiproton magnetic moments with 1.5 parts per billion fractional precision^7,8, which improved upon previous best measurements⁹ by a factor of greater than 3,000. Here we report on a new comparison of the proton/antiproton charge-to-mass ratios with a fractional uncertainty of 16 parts per trillion. Our result is based on the combination of four independent long-term studies, recorded in a total time span of 1.5 years. We use different measurement methods and experimental set-ups incorporating different systematic effects. The final result, [Formula: see text], is consistent with the fundamental charge-parity-time reversal invariance, and improves the precision of our previous best measurement⁶ by a factor of 4.3. The measurement tests the standard model at an energy scale of 1.96 × 10^-27 gigaelectronvolts (confidence level 0.68), and improves ten coefficients of the standard model extension¹⁰. Our cyclotron clock study also constrains hypothetical interactions mediating violations of the clock weak equivalence principle (WEP_cc) for antimatter to less than 1.8 × 10^-7, and enables the first differential test of the WEP_cc using antiprotons¹¹. From this interpretation we constrain the differential WEP_cc-violating coefficient to less than 0.030.

[Does the announcement of cancer at the time of Non Muscle-Invasive Bladder Cancer diagnosis affect quality of life and adherence of patients? Data from the French prospective cohort VICAN]

INTRODUCTION

The information provided at the time of diagnosis of Non Muscle-Invasive Bladder Cancer (NMIBC) is highly variable. Well-informed patient are more involved in shared decisions. The objective of our study was to assess the information perceived by the patient at the time of NMIBC diagnosis and its impact on quality of life.

METHODS

The VICAN french cohort involved a representative sample of 4174 cancer patients and 5 years survivors. Patients reported outcomes (PROs) were collected by phone and self-questionnaire. Among the 118 NMIBC patients, the term used to define the pathology at diagnosis was prospectively evaluated. The impact on quality of life (using SF-12, EORTC-QLQ-C30 and HAD scale) and on adherence to the care protocol (endoscopic monitoring) has been assessed.

RESULTS

Only 26.8% of patients reported hearing the word « Cancer » at the time of NMIBC diagnosis. Conversely, 73.2% of them reported others terms, including « Tumor » (22%), « Polyp » (24%), and « Carcinoma » (17.1%). There was no difference in terms of physical, mental quality of life and anxiety, regardless of the term used. Adherence to the follow-up endoscopic protocol was better in the group of patients hearing the word "Cancer".

CONCLUSION

Three quarters of patients treated for NMIBC did not integrate the concept of « Cancer » at the time of diagnosis. Quality of life and anxiety did not differ significantly depending on the term used at diagnosis. However, adherence to care protocol appears to be higher when using the word "Cancer".

LEVEL OF EVIDENCE

3.

Sympathetic cooling of a trapped proton mediated by an LC circuit

Efficient cooling of trapped charged particles is essential to many fundamental physics experiments1,2, to high-precision metrology3,4 and to quantum technology5,6. Until now, sympathetic cooling has required close-range Coulomb interactions7,8, but there has been a sustained desire to bring laser-cooling techniques to particles in macroscopically separated traps5,9,10, extending quantum control techniques to previously inaccessible particles such as highly charged ions, molecular ions and antimatter. Here we demonstrate sympathetic cooling of a single proton using laser-cooled Be+ ions in spatially separated Penning traps. The traps are connected by a superconducting LC circuit that enables energy exchange over a distance of 9 cm. We also demonstrate the cooling of a resonant mode of a macroscopic LC circuit with laser-cooled ions and sympathetic cooling of an individually trapped proton, reaching temperatures far below the environmental temperature. Notably, as this technique uses only image-current interactions, it can be easily applied to an experiment with antiprotons1, facilitating improved precision in matter-antimatter comparisons11 and dark matter searches12,13.

Methanogenic response to long-term permafrost thaw is determined by paleoenvironment

Methane production in thawing permafrost can be substantial, yet often evolves after long lag phases or is even lacking. A central question is to which extent the production of methane after permafrost thaw is determined by the initial methanogenic community. We quantified the production of methane relative to carbon dioxide (CO2) and enumerated methanogenic (mcrA) gene copies in long-term (2-7 years) anoxic incubations at 4 °C using interglacial and glacial permafrost samples of Holocene and Pleistocene, including Eemian, origin. Changes in archaeal community composition were determined by sequencing of the archaeal 16S rRNA gene. Long-term thaw stimulated methanogenesis where methanogens initially dominated the archaeal community. Deposits of interstadial and interglacial (Eemian) origin, formed under higher temperatures and precipitation, displayed the greatest response to thaw. At the end of the incubations, a substantial shift in methanogenic community composition and a relative increase in hydrogenotrophic methanogens had occurred except for Eemian deposits in which a high abundance of potential acetoclastic methanogens were present. This study shows that only anaerobic CO2 production but not methane production correlates significantly with carbon and nitrogen content and that the methanogenic response to permafrost thaw is mainly constrained by the paleoenvironmental conditions during soil formation.

SoilTemp: A global database of near-surface temperature

Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries across all key biomes. The database will pave the way toward an improved global understanding of microclimate and bridge the gap between the available climate data and the climate at fine spatiotemporal resolutions relevant to most organisms and ecosystem processes.

Development and use of a Biological Rhythm Interview

Introduction:

As several lines of evidence point to irregular biological rhythms in bipolar disorder, and its disruption may lead to new illness episodes, having an instrument that measures biological rhythms is critical. This report describes the validation of a new instrument, the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN), designed to assess biological rhythms in the clinical setting.

Methods:

Eighty-one outpatients with a diagnosis of bipolar disorder and 79 control subjects matched for type of health service used, sex, age and educational level were consecutively recruited. After a pilot study, 18 items evaluating sleep, activities, social rhythm and eating pattern were probed for discriminant, content and construct validity, concurrent validity with the Pittsburgh Sleep Quality Index (PSQI), internal consistency and test-retest reliability.

Results:

A three-factor solution, termed sleep/ social rhythm factor, activity factor and feeding factor, provided the best theoretical and most parsimonious account of the data; items essentially loaded in factors as theoretically intended, with the exception of the sleep and social scales, which formed a single factor. Test-retest reliability and internal consistency were excellent. Highly significant differences between the two groups were found for the whole scale and for each BRIAN factor. Total BRIAN scores were highly correlated with the global PSQI score.

Discussion:

The BRIAN scale presents a consistent profile of validity and reliability. Its use may help clinicians to better assess their patients and researchers to improve the evaluation of the impact of novel therapies targeting biological rhythm pathways.

[Safety of Hyperthermic IntraVEsical Chemotherapy (HIVEC) for BCG Unresponsive Non-Muscle Invasive Bladder Cancer Patients]

INTRODUCTION

There is increasing evidence that Hyperthermic Intravesical Chemotherapy is an effective treatment for non-muscle invasive bladder cancer (NMIBC). HIVEC (COMBAT BRS system) is an innovative hyperthermia delivering device. The aim of our study is to evaluate tolerance and safety of HIVEC in patients with BCG-refractory NMIBC.

MATERIALS AND METHODS

In this study, we included 22 patients between January 2017 and April 2018. The treatment consisted in a weekly instillation of Hyperthermic Mitomycin for a total of 6 weeks, with a follow-up every 3 months. In order to evaluate the tolerance, patients filled a questionnaire before each instillation. We analyzed collected data to evaluate safety and efficiency of the treatment after one year.

RESULTS

Among 22 patients included, no patient suffered from severe side effects. The minor side effects reported were : urinary urgency (40,1 %), urinary pain (40,1%), macroscopic hematuria (4,5%). The IPSS score didn't significantly varied before and after instillations (mean IPSS: 10.8 versus 10.1, p=0.77). The mean follow-up was 11.2 months. The recurrence rate was 27,3% with an average time to recurrence of 7.36 months. Two patients (9.1%) presented a progression to muscle-invasive disease. Four patients (18,2%) had a radical cystectomy.

CONCLUSION

Hyperthermic Mitomycin using the HIVEC® device is a rather safe and well tolerated treatment. Efficiency remains partial as 27.3% of patients experienced recurrence during the first year. These data should be confirmed by prospective multicentric studies.

[Is a routine second transurethral resection of the bladder still necessary after hexaminolévulinate photodynamic diagnosis-assisted TURBT?]

OBJECTIVES

The aim of our study was to assess the impact of blue light cystoscopy with hexaminolevulinate on residual tumor rates at second-look transurethral resection of the bladder (TURB).

MATERIAL AND METHODS

Among all patients undergoing TURB in our center between 2012 and 2017, 52 patients had a second-look after a first complete TURB with a delay<3months. We compare patients with standard white light cystoscopy/TURB then second-look blue light cystoscopy/re-TURB (group A, n=30) and patients with blue light cystoscopy/TURB at the initial procedure then white light cystoscopy/re-TURB (group B, n=22). The residual tumor rates at second-look, restaging and changing in therapeutic strategy, as well as recurrence free survival and progression rate were compared.

RESULTS

Residual tumor at the time of second-look cystoscopy was detected in 42.3% of cases in our cohort, with a significant difference between the two groups (63.3% in group A versus 0% in group B, <0.001). In group A, 16.7% (5/30) of patients had upstaging and/or upgrading at second-look cystoscopy, resulting in a change in therapeutic strategy in most cases (4/5) while none upstaging was observed in group B. In multivariate analysis, the use of luminofluorescence at the first TURB was the only independent predictive factor of residual tumor (P=0.0031).

CONCLUSION

The quality of the initial TURB, when performed by using blue light cystoscopy, had a significant impact on the rate of residual tumor at the second-look resection and could modify therapeutic strategy of NMIBC.

LEVEL OF EVIDENCE

4.

Measurement of Ultralow Heating Rates of a Single Antiproton in a Cryogenic Penning Trap

We report on the first detailed study of motional heating in a cryogenic Penning trap using a single antiproton. Employing the continuous Stern-Gerlach effect we observe cyclotron quantum transition rates of 6(1)  quanta/h and an electric-field noise spectral density below 7.5(3.4)×10^{-20}  V^{2} m^{-2} Hz^{-1}, which corresponds to a scaled noise spectral density below 8.8(4.0)×10^{-12}  V^{2} m^{-2}, results which are more than 2 orders of magnitude smaller than those reported by other ion-trap experiments.

The survival impact of neoadjuvant hormonal therapy before radical prostatectomy for treatment of high-risk prostate cancer

BACKGROUND

Several randomized controlled trials assessed the outcomes of patients treated with neoadjuvant hormonal therapy (NHT) before radical prostatectomy (RP). The majority of them included mainly low and intermediate risk prostate cancer (PCa) without specifically assessing PCa-related death (PCRD). Thus, there is a lack of knowledge regarding a possible effect of NHT on PCRD in the high-risk PCa population. We aimed to analyze the effect of NHT on PCRD in a multicenter high-risk PCa population treated with RP, using a propensity-score adjustment.

METHODS

This is a retrospective multi-institutional study including patients with high-risk PCa defined as: clinical stage T3-4, PSA >20 ng ml^-1 or biopsy Gleason score 8-10. We compared PCRD between RP and NHT+RP using competing risks analysis. Correction for group differences was performed by propensity-score adjustment.

RESULTS

After application of the inclusion/exclusion criteria, 1573 patients remained for analysis; 1170 patients received RP and 403 NHT+RP. Median follow-up was 56 months (interquartile range 29-88). Eighty-six patients died of PCa and 106 of other causes. NHT decreased the risk of PCRD (hazard ratio (HR) 0.5; 95% confidence interval (CI) 0.32-0.80; P=0.0014). An interaction effect between NHT and radiotherapy (RT) was observed (HR 0.3; 95% CI 0.21-0.43; P<0.0008). More specifically, of patients who received adjuvant RT, those who underwent NHT+RP had decreased PCRD rates (2.3% at 5 year) compared to RP (7.5% at 5 year). The retrospective design and lack of specific information about NHT are possible limitations.

CONCLUSIONS

In this propensity-score adjusted analysis from a large high-risk PCa population, NHT before surgery significantly decreased PCRD. This effect appeared to be mainly driven by the early addition of RT post-surgery. The specific sequence of NHT+RP and adjuvant RT merits further study in the high-risk PCa population.

Sixfold improved single particle measurement of the magnetic moment of the antiproton

Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.

[Oncological results of active surveillance in prostate cancer: A retrospective multicentric cohort]

PURPOSE

To report oncological outcomes of patients with prostate cancer undergoing active surveillance according to SURACAP criteria.

METHODS

This multicentric study included patients who were initially treated with active surveillance for localized prostate cancer according to the SURACAP criteria. The duration of active surveillance as well as the causes of discontinuing the protocol and the definitive pathological results of patients who further underwent radical prostatectomy were retrospectively evaluated. The predictors of discontinuing active surveillance were assessed using a univariable Cox Model. In addition, the predictive value of initial MRI was assessed for patients who performed such imagery.

RESULTS

Between 2007 and 2013, 80 patients were included, with a median age of 64 years [47-74]. Median follow-up was 52.9 months [24-108]. At 5 years follow-up, 43.4% patients were still under surveillance. Among patients that underwent surgery, 17.8% had an extra-capsular extension. The risk of discontinuing was not significantly greater for patients with tumor size of 2 or 3mm versus 1mm (HR=0.9 [0.46-1.75], P=0.763), 2 positives cores versus 1 (HR=0.98 [0.48-2.02], P=0.967), T2a vs. T1c stage (HR=2.18 [0.77-6.18], P=0.133), increased PSA level (HR=1 [0.96-1.15], P=0.975) or the patient's age (HR=1 [0.93-1.16], P=0.966). Among the 50 patients who performed initial MRI, the results of such imagery was not significantly associated to the risk of discontinuing active surveillance MRI (HR=1.49 [0.63-3.52], P=0.36).

CONCLUSION

Although this study reveals a high rate of release from active surveillance at 5 years, the rate of extra-capsular tumors reported in the group of patients that underwent surgery is among the lowest in literature.

LEVEL OF EVIDENCE

4.